Question

solve using complete the square: 2x^2-4x-8=0

Answer 1

Hint:

2x^2-4x-8=0

2x^2-4x=8

2(x^2-2x)=8

2(x^2-2x+1-1)=8

2((x^2-2x+1)-1)=8

2(x^2-2x+1)-2=8

2(x^2-2x+1)=8+2

2(x^2-2x+1)=10

2(x-1)^2=10

Answer 2

why did you do +1 and -1

Answer 3

because the +1-1 is really +0

Answer 4

and that doesn't change anything

Answer 5

you add and subtract 1 to complete the square

Answer 6

@jim_thompson5910 Why didn't you divide both sides by 2 as your first step?

Answer 7

you can do that, but i just kept it for some reason

it doesn't matter either way

Answer 8

Ok, thanks. I was just wondering if there was a specific reason for not doing it.

Answer 9

no i guess i just forgot about it and copied/pasted it down the line